An electric power converter is used for converting a DC power to an AC power, or for converting an AC power to a DC power. For example, a DC power is generated by a solar battery site assembled in a desert, and the DC power is converted to the AC power. In such a case, an electric power converter which converts a DC power to an AC power is used. In this case, the power converter produces a sinusoidal AC voltage and sinusoidal AC current from the output terminal. According to another example, an AC power is generated by an AC generator, and the AC power is converted to the DC power. In such a case, an electric power converter which converts an AC power to a DC power is used. In this case, the power converter produces a DC voltage and a DC current from the output terminal.